specifications - FAACO - Federal Aviation Administration Contract ...

FTWIC-2235June 20098. INTERCONNECTIONS: All connections to the single point ground systemshall be made on ground plates or buses. Split bolts, clamps and other connectionsto previously installed cables are not allowed.9. LABELING, CABLES: Trunk and branch cables shall be color coded greenwith a bright yellow tracer. Where cables are concealed and not color coded, anyexposed portion of the cable and each end of the cable for a minimum length of 2feet shall be color coded by green tape overlaid with bright yellow tape to formthe tracer. Where routed through raceways or wireways, color coding shall bevisible by opening any cover. Where conductors are routed through cable trays,color coding 4 inches wide shall be applied at intervals not exceeding 3 feet.10. LABELING, GROUND PLATES: All ground plates shall be provided with aclear plastic protective cover spaced 3/4 inch from the plate and extending 1 inchbeyond each edge. This cover shall have a green label with distinguishing brightyellow slashes attached bearing the caption: "CAUTION, ELECTRONICSINGLE POINT GROUND" in black 3/8 inch high characters.I. Provide a Multipoint grounding system throughout the facilities in accordance with thisspecification.1. GENERAL: The protection of electronic equipment against potential differencesand static charge buildup shall be provided by interconnecting all non-currentcarrying metal objects to an electronic multipoint ground system that iseffectively connected to the earth electrode system. The multipoint ground forelectronic equipment systems consists of electronic equipment, racks, frames,cabinets, conduits, raceways, wireways, cable trays enclosing electronicconductors, structural steel members, and conductors used for interconnections.The electronic multipoint ground system shall also provide multiple lowimpedance paths between various parts of the facility, electronic equipmentwithin the facility, and any point within the system and the earth electrodesystem to minimize the effects of spurious currents that may be present in theground system. It is essential that no power or single point grounds utilize thissystem. The multipoint ground system is also not to be used as a signal returnpath.2. RAISED FLOORS: Electronic equipment rooms may utilize a properly bonded,electrically continuous, grounded raised floor, consisting of a bolted grid, or rigidgrid system as part of an electronic grounding system.3. GROUND PLATES, CABLES AND PROTECTION: The electronic multipointground system shall not replace the equipment grounding conductor routed withthe phase and neutral conductors as required by the NEC. At least twoconnections between the multipoint ground system and the earth electrode systemshall be provided. One connection shall be provided by a 500 KCMIL orequivalent copper cable connected between the main ground plate and the earthelectrode system. In buildings without structural steel members, a secondconnection shall be provided by a 500 KCMIL or equivalent copper cableconnected between the earth electrode system and a supplemental ground plateon the opposite side of the facility. The cable shall be exothermically welded tothe earth electrode system and bolted to the ground plate or bus with a UL16450-4